Hi guys,
I've noticed that the "Brave New World" achievement has not unlocked for me and on further investigation understand this to be the opening story mission, so not sure why this has happened. As far as I know, there is no way to replay this mission without restarting the game and losing all my progress.
I started on an Xbox One X and then moved across to an Xbox Series X if that helps your investigation.
Hoping there is an easy way to resolve this.